Sand-mulling apparatus

ABSTRACT

A foundry-sand-mulling apparatus having a cylindrical mulling bowl within which there is provided a novel form of sandelevating plow construction having three functional components, namely, a main lift plow in the form of a sand scoop pan, a side wing which prevents sand from spilling over the inner side edge of the main lift plow and also compresses the sand against the sidewall of the bowl during travel of the plow construction in a circumferential direction in the bowl and a side plow which directs sand onto the main lift plow.

ilnited tates Fatent [72] Inventor Clifford E. Wenninger Libertyville, 1.11.

[21] Applv No. 19,445

[22] Filed Mar. 13, 1970 [45] Patented [73] Assignee Aug. 31, 1971 Pettibone Corporation Chicago, Ill.

Continuation of application Ser. No. 684,192, Nov. 20, 1967, now abandoned.

[54] SAND-MULLINS APPARATUS 4 Claims, 6 Drawing Figs.

[52] U.S.Cl 241/110, 241/124 [51] Int. Cl ..B02c 15/00, B02c 23/00 [50] Field of Search 241/105,

108,110,112,l18,l24,123, 129,162,166; 259/107, 108, 178 A, DIG. 4

[56] References Cited UNITED STATES PATENTS 2,303,319 12/1942 Beardsley et a1 241/129 X 3,256,573 6/1966 Hunter 241/110 X Primary Examiner-Lester M. Swingle Assistant Examiner-Gary L. Smith Attorney-Norman H. Gerlach ABSTRACT: A foundry-sand-mulling apparatus having a cylindrical mulling bowl within which there is provided a novel form of sand-elevating plow construction having three functional components, namely, a main lift plow in the form of a sand scoop pan, a side wing which prevents sand from spilling over the inner side edge of the main lift plow and also compresses the sand against the sidewall of the bowl during travel of the plow construction in a circumferential direction in the bowl and a side plow which directs sand onto the main lift plow.

PATENTEfl-Ausal I97! SHEET 1 OF 2 INVENTOR CLIFFORD E. WENNI NGER SAND-MULLING APPARATUS The present invention is a continuation of my pending U.S. Pat. application S'er. No. 684,192, filed on Nov. 20, 1967, now abandoned and entitled SAND MULLING APPARATUS."

The present invention relates to an apparatus for mulling or conditioning foundry sand of the type which is used in connection with metal-casting operations.

It has long been the practice after a casting operation to remove the packed and heated sand from the flasks and then, in order to condition the sand for reuse in the flasks in connection with a future casting operation, to mull the sand by placing it, together with any suitable bonding material such, for example, as clay, in a large-sized cup-shaped receptacle or bowl and then subjecting it to the action of rotary mulling elements and, in addition, deflectorlike plows which successively elevate the portion of the sand into the circular path of travel of the mulling elements. The mulling operation serves to break up any lumps in the sand also serves to aerate and resultantly to cool the sand and, in addition, to mix the bonding material intimately with the sand. During the mulling operation, water is usually added to the sand in order to moisten it, thus increasing the bonding strength of the sand when it is ultimately used in a casting operation.

It is obvious, therefore, that the efficiency of any sandmulling apparatus is largely dependent upon the ability of the apparatus to effect intimate mixing of the sand, the bonding agent, and the water in the proper amounts and in a batch cycle of minimum duration. A batch cycle may be said to be complete when each grain of sand becomes completely coated with a skin of the bonding agent and the thus coated sand grains have adhered thereto the proper amount of moisture with little or no excess of free bonding agent or water remaining within the mulling chamber which is constituted by the interior of the cup-shaped bowl of the mulling apparatus. The attainment of this condition in the shortest possible period of mulling time is the aim of all present-day mulling apparatus.

The type of sand mulling which is performed by a mulling apparatus of the character briefly outlined above is commonly referred to as pressure extrusion mulling by reason of the fact that the apparatus invariably employs as the rotary mulling elements heavy, horizontally extending, mulling wheels which exert great pressure upon the sand undergoing mulling by squeezing it against the cylindrical sidewall of the bowl, thus inducing a shearing action of the sand particles against one another as well as against said cylindrical sidewall. Such shearing action is extremely effective in intimately mixing particles of clay or other bonding material with increments of moisture. With the depletion of many natural sand deposits of high clay content and the consequent replacement by foundries of natural sand with synthetic mixtures having a low clay content, greater pressures have been employed in the belief that a granule-to-granule shearing action under high pressure will enhance the desired sand grain coating.

The present mulling apparatus is predicated upon entirely different theoretical considerations. During mulling, sand grains respond to mechanical force by striving to unite or gather together in such a manner as to offer greater resistance to the application of mulling force by the mulling wheels. A transformation of sand grains into clusters commences as soon as water is added by introducing it into the receptacle bowl of the mulling apparatus. Subsequently, when clay is added, clay balls are formed and resultant sand and clay clusters appreciably restrict the ability of pressure by the mulling wheels to effect the desired extrusion. For an individual grain to acquire a more complete coating, it must be separated from a cluster so that the otherwise protected surfaces thereof may receive additional bond and also surrender excess bond to other grains, thus accelerating complete bonding of all of the sand particles. Since clusters are inevitable with any type of foundry sand mulling, these clusters must be brokenup as soon as they tend to form and the present invention affords a novel means in the form of specially designed plow constructions which operate entirely independently of any associated ,rotary mulling wheels to maintain an unrestricted assembly and subsequent breakup of clusters so that uniform coating of the sand grains will be attained in a minimum of mulling time. The provision of a foundry-sand-mulling apparatus employing such plow constructions constitutes the principal object of the present invention.

In carrying out this particular object, the invention contemplates the provision of a sand-mulling apparatus which, in the main, is structurally similar to a horizontal mulling wheel apparatus in that it is provided with a generally cylindrical, cupshaped mulling receptacle or bowl within which there is mounted for rotation about a vertical axis the usual horizontally extending hub which carries the aforementioned novel plows and may also, but not necessarily, carry a set of horizontally extending, rotatably mounted, mulling wheels. The general arrangement may be similar to that which is shown and described in U.S. Pat. No. 3,256,573, granted on June 21, 1966 and entitled SAND MULLING APPARATUS." The mulling bowl, the rotatable hub or crosshead, the drive mechanism for the hub or crosshead, the door-closed opening for unloading the mulled sand from the bowl, and the mulling wheels (if employed) may be substantially the same as the equivalent components or structures of the mulling apparatus of said patent, the principal difference residing in the configuration of the novel plow constructions which differ both in structure and function from those of the mulling apparatus of the patent. The present sand-mulling apparatus is, therefore, capable of being manufactured as an original apparatus or, alternatively, it may be constructed by suitable modification of an existing mulling apparatus. In either event, the essential features of the invention are preserved.

Other objects of the invention and the various advantages and characteristics of the present mulling apparatus will be apparent from a consideration of the following detailed description.

In the accompanying two sheets of drawings forming a part of this specification, several illustrative embodiments of the invention are shown.

In these drawings:

FIG. 1 is a sectional view taken substantially centrally and vertically through a mulling apparatus employing a preferred form of plow construction embodying the principles of the present invention, certain parts being broken away and other parts being shown in elevation in order more clearly to reveal the nature of the invention;

FIG. 2 is a top plan view of the improved mulling apparatus of FIG. 1;

FIG. 3 is an underneath or bottom perspective view of the rotatable hub, such view illustrating specifically the manner in which the various novel plow constructions are attached to the hub;

FIG. 4 is an enlarged vertical sectional view taken on the line 4-4 of FIG. 2;

FIG. 5 is an enlarged vertical sectional view taken on the line 55 of FIG. 2; and

FIG. 6 is a fragmentary perspective view looking radially inwardly toward the hub and in the vicinity of one of the plow constructions.

Referring now to the drawings in detail and in particular to FIGS. 1 and 2, the apparatus which is shown therein constitutes one exemplary form of the invention although not necessarily the commercial embodiment thereof. The apparatus is particularly designed and adapted for use in a foundry or similar establishment and serves as a means or instrumentality for mulling and conditioning molding sand preparatory to use of the sand in flasks during a casting operation. Briefly, the apparatus involves in its general organization a mulling bowl 10 within which there is centrally disposed a rotatable unitary sand-mulling assembly 11. The latter comprises a central, horizontally extending hub 12, such hub being mounted for rotation about a vertical axis and serving to carry a series of two mulling elements in the form of horizontally disposed wheels 14, and, in addition, a series of two deflectorlike plow constructions 16, the latter being secured to the periphery of the hub and constituting the principal feature or point of novelty of the present invention. Although two of the mulling wheels and two of the plow constructions are illustrated in the drawings herein for exemplary or disclosure purposes, it is to be distinctly understood that a greater number of such wheels and plow constructions may be employed if desired. Insofar as the mulling wheels 14 are concerned, they are not essential to the present invention and may be omitted entirely if desired. However, under certain circumstances, the wheels augment the action of the plow constructions 16 in a beneficial manner and, as a consequence, they have been included herein as a part of the overall disclosure. Regardless of the number of wheels and plow constructions which may be employed in any given installation, the circumferential spacing thereof will always be equal sothat in the illustrated form of the invention, the wheels are disposed 180 apart on the periphery of the hub 12 and the plow constructions are likewise disposed 180 apart but are positioned midway between the two mulling wheels.

The mulling wheels 14 are rotatably mounted on the peripheral portion of the hub 12 and thus are bodily revolvable about the vertical axis of the hub as well as being rotatable about their own individual vertical axes. The plow constructions 16 are fixedly secured to the peripheral portion of the hub in a manner to be described hereafter.

The foundry-sand-mulling apparatus further includes an air supply duct 18 for introduction of air under pressure to the interior of the bowl 110 for sand aeration and cooling purposes, a water supply pipe 20 for introducing water into the bowl for admixture with the sand, and an electric motor M. The latter is operatively connected through the medium of a gear reduction device 22 to the aforementioned rotary sand-mulling assembly 11 and serves when energized to drive the same. The apparatus is essentially of the batch type and is adapted to mull and condition successive batches of new or previously used molding sand. The batches of sand may be periodically introduced into the bowl through the open upper rim thereof by way of an endless conveyor or other means (not shown). The bowl is removably supported upon a hollow base casting 24 which, in turn, is mounted on a horizontally elongated main supporting frame 26. A pivoted damper 27 in the air duct 18 serves to control the flow of air under pressure into the interior of the bowl 10 via the base casting 24 and is operable under the control of an air cylinder 28.

Still referring to FIGS. 1 and 2, the bowl 10 is of a composite nature and comprises a substantially flat annular bottom wall 30 and an upstanding rubber-lined cylindrical sidewall 32, the liner 34 for which is of arcuate sectional design. The bowl sidewall presents a circular upper rim 36 which is provided with a narrow continuous, outwardly extending rim flange 38. The bottom wall 30 has formed therein a central opening 40 in communication with the interior of the base casting 24 in order to permit air under pressure from the air duct 18 to enter the bowl interior. The bowl 10 is removably clamped to the base casting 24 by means of an annular series of spaced'apart clamp assemblies 42, each of which embodies a clamp lug 44 which is welded to the bowl sidewall 32 at a point adjacent to the bottom rim thereof. Each clamp assembly 42 also embodies a hooklike clamping arm 46 and, in addition, a capscrew 47 which projects through the clamping arm and is threadedly received in the associated clamp lug 44. The clamping arms of the clamp assemblies 42 are adapted to hook beneath a circular depending marginal rib 48 on the base casting 24 so that when the capscrews 47 are tightened, the adjacent portion of the bowl will be drawn downwardly hard against the base casting on which it securely seats.

A discharge opening 50 interrupts the sidewall 32 of the bowl 10 throughout an arc of limited extent and this opening 50 is normally adapted to be closed by a hinged arcuate door 52 having associated therewith a rubber liner 54 which constitutes a continuation of the sidewall liner 34 when the door is in its closed position. The door 52 is hinged on a support 56 and is movable between open and closed positions with respect to the discharge opening 50 under the control of an air cylinder 58. The door structure and the control mechanism therefor constitute no part of the present invention and, therefore, the details thereof are not fully disclosed herein. For a more detailed understanding of this door structure, reference may be had to aforementioned U.S. Pat. No. 3,256,573. The novelty of the present invention resides rather in the nature of the rotatable sand-mulling assembly 11 and particularly in the nature and character of the plow constructions 16 which are associated with the assembly and will be described in detail presently.

The rotary sand-mulling assembly 11 which, as previously stated, embodies the hub 12, the mulling wheels 14 and the plows 16, is rotatably mounted on a vertically extending pedestal 60 which is fixedly connected to and extends upwards from the base casting 24 and has suitably mounted thereon one or more roller bearings 62. A vertical shaft 64 is journaled in the roller bearing or bearings 62 and is arranged so that the upper end thereof projects upwards beyond the pedestal 60 and is drivingly attached to the central portion of the hub 12. The lower end of the shaft 64 is provided with a splined section 66 which carries a gear 68, the latter constituting the output gear of the gear reduction device 22. The input shaft 70 of the gear reduction device carries a driven pulley 72. A cooperating driving pulley 74 which is associated with and driven by the motor M is connected to the pulley 72 by an endless belt 76, thus completing a power drive from the motor M to the rotatable sand-mulling assembly 11.

Referring now to the drawings the hub 12 of the rotary sand-mulling assembly 11 may assume various shapes but preferably is generally of the same configuration as the hub of the sand-mulling apparatus which is shown and described in aforementioned U.S. Pat. No. 3,256,573, such a hub lending itself admirably to use in connection with the present invention. The hub 12 is of a composite nature and includes an annular, horizontally extending casting having the general shape characteristics of a truncated convex paraboloid of revolution of the type wherein a parabolic arc is revolved about an axis normal to the axis of the parabola and tangent to the parabola at its axis. The truncated upper portion of the casting 80 is surmounted by a sheet metal cone 82, the apex part of which is rounded as at 84. The hub 12 as a whole thus takes on a mushroomlike appearance when considered in connection with the pedestal 60 on which it is mounted. The entire upper surface of the hub 12 including the paraboloidshaped casting 81B and the cone 82 is polished to a high degree of smoothness to reduce the coefficient of friction between the hub and the sand within the bowl 10 and thus reduce to a minimum any tendency for the sand to cling to the upper surface of the hub. The partly paraboloidal and partly conical contour of the upper surface of the hub 12 is so designed that the angle of repose of sand particles on any given point thereof will approach a zero angle when the hub is set into motion at normal operating speeds.

The details of the aforementioned driving connection between the upper end of the shaft 64 and the hub 12 have not been fully disclosed herein since they are not directly or necessarily applicable to the present invention and numerous forms of driving connections may be employed if desired. However, in FIG. 3, the casting 80 is shown as being formed with a central downwardly projecting annular pilot boss 86 which is formed as a part of a mounting web 88, the latter being provided with holes 90 (see FIG. 3) for bolts (not shown) by means of which the hub as a whole may be attached to a mating radially extending flange 92 (see FIG. 1) on the upper end of the shaft 64.

Referring now to FIGS. 2 to 6, inclusive, the two horizontally disposed mulling wheels 14 are of conventional or standard construction and each is rotatably mounted for individual rotation on the upper end of a supporting arm 100,0f

tapered design. The arms 100 are formed as integral parts of the hub near the periphery thereof and are inclined upwardly and outwardly. They are of streamline design which is to say that they merge gradually with the parabolic contour of the upper surface of the hub 12. The upper surfaces of the wheels are preferably in the form of paraboloids. The periphery of each wheel 14 is provided with a solid rubber or other elastomeric tire 102 as is customary in connection with a mulling apparatus of the general type under consideration and such tire is designed for cooperation with the elastomeric liners 34 and 54 of the bowl 110 and the discharge door 52 respectively in effecting the desired mulling action on the sand within the bowl interior.

Still referring to FIGS. 2 to 6, inclusive, the plow constructions 16, as heretofore mentioned, constitute the principal novelty of the present invention and each plow construction is comprised of three functional components including a main lift plow 104 of inclined scooplike design, a side wing 106 which extends generally upwardly from the inner edge of the lift plow 104, and a side plow which projects a considerable distance beyond the lift plow in the leading direction of movement thereof. These side plows 108 assume generally tangential positions with respect to the hub 12 and the inner ends thereof bear against an annular rib 110 (see FIG. 3) which depends from and is concentrically positioned with respect to the underneath side of the hub. A relatively heavy gauge, horizontally extending mounting plate 112 is welded to the central portion of the upper margin of each side plow 108 and is connected by bolts 113 to the adjacent portion of the peripheral region of the hub on the underneath side thereof. Each side wing 106 is in the form of an angular plate having a planar trailing section 114 (see FIG. 6) which is substantially normal to a radius of the hub, and a planar leading section 1 16 which is inclined inwardly at an obtuse angle with respect to the leading edge of the trailing section 114, and is slightly inclined inwardly and upwardly with respect to the bottom wall 30 of the bowl 10. The outer end regions 117 of the side plows 108 merge gradually into and are connected to the front lower corner portions of the leading sections 116 of the side wings 106 as clearly shown in FIG. 3.

As previously indicated, the left plows 104 are disposed in edge-to-edge relationship with respect to the side wings 106, the inner edges of the left plows engaging both sections 114 and 116 of the side wings. Angle pieces 120 (see FIG. 3) have horizontal portions bolted as at 122 to the underneath sides of the left plows 104 and vertical portions bolted to the lower edge region of the trailing sections 114 of the side wings 106, thus reinforcing the side wings and left plows with respect to each other,

The specific function of the plow constructions 16 will be described in detail presently, the mode of operation thereof being largely a result of the shape of the lift plows 104, the side wings 106, and the side plows 108 and their positional relationship or orientation with respect to one another and to the bottom wall 30 and the sidewall 32 of the mulling bowl 10. For the present, it is deemed sufficient to state that the left plows 104 serve to elevate the sand within the bowl from the bottom wall 30 thereof and place the same in the path of movement of the side wings 106 so that the latter may, by a combined shearing and smearing action against the liner 34 of the bowl sidewall 32, exert sufficient pressure on the sand as continuously to inhibit the formation of clay conglomerations or sand clusters, as well as to break up such clusters as may be formed before they reach large proportions.

As best illustrated in FIG. 5, each left plow 104 is of platelike construction and is disposed at an angle of approximately 20 with respect to the horizontal plane of the bottom wall 30 of the mulling bowl 110. The forward edge of each plowpan 8 is curved as indicated at 124 and lies close to the bowl bottom wall 30. Both sections 114 and 116 of each side wing 106 are disposed in respective planes which assume relatively steep angles with respect to the bottom wall 30 of the bowl, the trailing section 114 extending normal to a radius of the hub and the leading section 116 extending from the forward edge of the trailing section 114 at an obtuse angle. The upper edge of each side wing 106 may lie close to or in the horizontal plane of the lower circular rim of the hub 12 as shown in FIG. 6. Each side plow 108 travels close to the bottom wall 30 of the bowl so as to exert a sweeping action on the sand and force the same outwardly and into the path of its associated lift plow 104. As shown in FIG. 3, two diametrically opposite sweeper arms 126 have their inner ends welded to the aforementioned annular rib and extend tangentially with respect to such rib so that they function in the same manner as the side plows 108 to sweep sand radially outwards of the bowl bottom.

In the operation of the form of mulling apparatus which is shown in FIGS. 1 to 6, inclusive, the mulling bowl 10 is charged through the open upper rim 36 of the sidewall 32 with a batch of molding sand to be mulled, mixed or conditioned and the prerequisite quantity of bonding agent, utilizing any suitable charging means such as an overhead conveyor or by the simple expedient of batch dumping the sand and bonding agent into the bowl. Thereafter, upon energization of the electric motor M, the motor operates through the gear reduction device 22 to rotate the vertical drive shaft 64,and thus, cause rotation of the hub 12 in the direction indicated by the arrows in FIGS. 2, 3 and 6. It will be understood, of course, that the air cylinder 58 will previously have been operated to swing the door 52 into a closed position across the door opening 50, thus establishing for the bowl 10 a smooth, continuous cylindrical inner side surface by reason of the meeting edges of the elastomeric liners 34 and 54.

As soon as rotation of the hub 12 has commenced, the air cylinder 28 will be operated to open the damper 27 in order to admit air under pressure to the interior of the bowl 10 through the hollow base casting 24 and the central opening 40 in the bowl bottom wall 30. Similarly, at this time, and under the control of suitable valve means (not shown), water at a predetermined rate of flow is admitted to the bowl through the supply pipe 20. A considerable amount of such water and air is flung radially outwardly beneath the hub 12 by the action of the sweeper arms 126, as well as the side plows 108.

During rotation of the hub 12, the left plows 104 sweep around the peripheral region of the bowl bottom wall 30 and encounter the sand which has been swept radially outwardly by the side plows 108 and into the path of movement of these left plows. The downwardly and forwardly inclined left plows elevate the sand into the annular area which exists between the side wings 106 and the rubber-lined sidewall 32 of the bowl 10. The inwardly and upwardly inclined leading sections 116 of the side wings, in combination with the bowl sidewall 32, establish, in effect, revolving funnel structures which crowd the sand into the narrower annular area or space between the'trailing sections 116 and the sidewall 32 so that a smearing action on the sand takes place, the sidewall 32 constituting the smearing anvil and the side wings 106 constituting smearing spatulas, so to speak. In this manner, the formation of sand or clay clusters is inhibited and any such clusters as may have an opportunity initially to take form are immediately broken up and uniformly dispersed. Additionally, pressure is exerted upon the sand thereby enhancing the desired coating action as a result of pressure extrusion of the sand. The net result of this smearing action is that the sand aggregate develops higher strength as it rises and recycles from one plow construction to the other.

It is to be understood that in the exemplary form of plow construction illustrated herein, the particular weldments and bolting arrangements which have been resorted to constitute only one way in which the plow construction 16 may be caused to present the three major cooperating sand-impelling or sand-restraining surfaces outlined above, these surfaces consisting of the outer surface of the side plow 108 which throws the sand radially outwardly into the path of movement of the oncoming lift plow 104, the upper surface of such lift plow itself, and the outer surface of the side'wing 106 which confines the sand on the lift plow and restrains it from sliding off the inner edge of such lift plow.

It is to be observed that the mulling wheels 14 (if employed) are disposed at an elevation above the elevation of the plow constructions 16. This elevated sand is trailed by the mulling wheels 14 which ride through the elevated sand and by reason of the free rotation of these wheels, the latter act to compact the sand against the rubber-lined sidewall 32 of the bowl 10 in the usual manner of operation of such mulling wheels.

When the mulling operation has been completed, the door 52 is swung open in the manner previously described and under the influence of the air cylinder The parabolic hub 12 is maintained in operation and the flinging action of all of the parts that are associated therewith serves to throw the sand radially outwardly through the door opening 50 from whence it may be directed to and collected in a suitable receptacle.

The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In a mulling apparatus of the type that embodies a bowl adapted to receive therein a predetermined amount of granular material to be mulled and including a bottom wall and an upstanding cylindrical sidewall, a mulling assembly mounted for rotation in one direction about a vertical axis within the bowl and including a hub and a plurality of mulling plow constructions connected fixedly to and disposed outwards of the hub, arranged below the level of the hub and in circumferentially spaced relationship, and adapted for rotation bodily in unison with the hub, each plow construction including a platelike wing structure having an outer side face which opposes the inside face of the cylindrical wall of the bowl adjacent to the lower region of the latter, and having leading and trailing sections with respect to the direction of rotation of the mulling assembly, the leading section of said wing structure being inclined upwardly and inwardly with respect to the bowl bottom wall and being disposed for the most part at a greater distance from said sidewall than the trailing section to the end that it extends at an obtuse angle with respect to said trailing section, a side plow having its outer end connected to said leading section of the wing structure and its inner end fixedly secured to the hub, said side plow lying close to the bottom wall of the bowl and extending in a direction which is generally tangential with respect to the hub, whereby said side plow functions in the manner of a deflector for urging the granular material radially outwardly of the bowl and into the path of movement of the leading section of said wing structure, and means for rotating said mulling assembly in said one direction.

2. A mulling apparatus as set forth in claim l and including,

additionally, a lift plow projecting radially outwardly from the lower edge portion of each wing structure, said lift plow being disposed between the wing structure and the sidewall of the bowl, being inclined downwardly in the direction of movement of the associated plow construction, and having a leading edge positioned in close proximity to the bottom wall of the bowl to the end that the lift plow functions as a scoop for elevating the granular material encountered thereby.

3. A mulling apparatus as set forth in claim 2 and including, additionally, a series of mulling wheels eccentrically mounted on said hub above the level of the latter, there being one mulling wheel for each plow construction, each mulling wheel assuming a trailing position with respect to its associated plow construction and being in the form of a freely rotatable disklike member the periphery of which is designed for cooperation with the bowl sidewall during rotation of the hub for compacting the granular material which is elevated by the lift plow of its associated plow construction against said sidewall.

4. In a mulling apparatus of the type that embodies a bowl adapted to receive therein a predetermined amount of granular material to be mulled and including a bottom wall and an upstanding cylindrical sidewall, a mulling assembly mounted for rotation in one direction about a vertical axis within the bowl and including a hub and a mulling plow construction fixedly connected to and disposed outwards of the hub, arranged below the level of the hub, and adapted for rotation bodily with the hub, said plow construction including a platelike sand-scooping lift plow presenting an upper surface which is inclined downwardly and forwardly with respect to the direction of movement of the plow construction and having inner and outer side edges, said outer side edge being disposed in close proximity to said upstanding sidewall of the bowl, a platelike wing structure having an outer side face which opposes the inner face of the cylindrical wall of the bowl adjacent to the lower region of the latter, and embodying leading and trailing sections with respect to the direction of rotation of the mulling assembly, the trailing section extending upwards from the rear region of the inner edge of the lift plow, the leading section of said wing structure extending upwards from the front region of the inner portion of the left plow, being inclined upwardly and inwardly with respect to the bowl bottom, and being disposed for the most part at a greater distance from said sidewall than the trailing section to the end that it extends at an obtuse angle with respect to said trailing section, a side plow having its outer end connected to the front portion of said leading section of the wing structure and its inner end fixedly secured to the hub, said side plow lying close to the bottom wall of the bowl and extending in a direction which is generally tangential with respect to the hub, whereby the side plow functions in the manner of a deflector for urging the granular material radially outwardly of the bowl and into the path of movement of the leading section of said wing structure, and means for rotating said mulling assembly in said one direction.

Patent No. 3, 602, 442

Inventor(s) C] j ffi -d E flfinnjngex It is certified that error appears in the aboveand that said Letters Patent are hereby corrected as Dated August 31, 1971 identified patent shown below:

Claim 4, line 9, "platelike" should be --plate-like--;

line 15, "platelike" should be -plate-like--; and

line 22, "left" should be --lift-.

Signed and sealed this 2nd day of July 1974.

(SEAL) Attest:

EDWARD M.FLETCHER,JR.

Commissioner of Patents USCOMM-DC 00376-0 09 

1. In a mulling apparatus of the type that embodies a bowl adapted to receive therein a predetermined amount of granular material to be mulled and including a bottom wall and an upstanding cylindrical sidewall, a mulling assembly mounted for rotation in one direction about a vertical axis within the bowl and including a hub and a plurality of mulling plow constructions connected fixedly to and disposed outwards of the hub, arranged below the level of the hub and in circumferentially spaced relationship, and adapted for rotation bodily in unison with the hub, each plow construction including a platelike wing structure having an outer side face which opposes the inside face of the cylindrical wall of the bowl adjacent to the lower region of the latter, and having leading and trailing sections with respect to the direction of rotation of the mulling assembly, the leading section of said wing structure being inclined upwardly and inwardly with respect to the bowl bottom wall and being disposed for the most part at a greater distance from said sidewall than the trailing section to the end that it extends at an obtuse angle with respect to said trailing section, a side plow having its outer end connected to said leading section of the wing structure and its inner end fixedly secured to the hub, said side plow lying close to the bottom wall of the bowl and extending in a direction which is generally tangential with respect to the hub, whereby said side plow functions in the manner of a deflector for urging the granular material radially outwardly of the bowl and into the path of movement of the leading section of said wing structure, and means for rotating said mulling assembly in said one direction.
 2. A mulling apparatus as set forth in claim 1 and including, additionally, a lift plow projecting radially outwardly from the lower edge portion of each wing structure, said lift plow being disposed between the wing structure and the sidewall of the bowl, being inclined downwardly in the direction of movement of the associated plow construction, and having a leading edge positioned in close proximity to the bottom wall of the bowl to the end that the lift plow functions as a scoop for elevating the granular material encountered thereby.
 3. A mulling apparatus as set forth in claim 2 and including, additionally, a series of mulling wheels eccentrically mounted on said hub above the level of the latter, there being one mulling wheel for each plow construction, each mulling wheel assuming a trailing position with respect to its associated plow construction and being in the form of a freely rotatable disklike member the periphery of which is designed for cooperation with the bowl sidewall during rotation of the hub for compacting the granular material which is elevated by the lift plow of its associated plow construction against said sidewall.
 4. In a mulling apparatus of the type that embodies a bowl adapted to receive therein a predetermined amount of granular material to be mulled and including a bottom wall and an upstanding cylindrical sidewall, a mulling assembly mounted for rotation in one direction about a vertical axis within the bowl and including a hub and a mulling plow construction fixedly connected to and disposed outwards of the hub, arranged below the level of the hub, and adapted for rotation bodily with the hub, said plow construction including a platelike sand-scooping lift plow presenting an upper surface which is inclined downwardly and forwardly with respect to the direction of movement of the plow construction and having inner and outer side edges, said outer side edge being disposed in close proximity to said upstanding sidewall of the bowl, a platelike wing structure having an outer side face which opposes the inner face of the cylindrical wall of the bowl adjacent to the lower region of the latter, and embodying leading and trailing sections with respect to the direction of rotation of the mulling assembly, the trailing section extending upwards from the rear region of the inner edge of the lift plow, the leading section of said wing structure extending upwards from the front region of the inner portion of the left plow, being inclined upwardly and inwardly with respect to the bowl bottom, and being disposed for the most part at a greater distance from said sidewall than the trailing section to the end that it extends at an obtuse angle with respect to said trailing section, a side plow having its outer end connected to the front portion of said leading section of the wing structure and its inner end fixedly secured to the hub, said side plow lying close to the bottom wall of the bowl and extending in a direction which is generally tangential with respect to the hub, whereby the side plow functions in the manner of a deflector for urging the granular material radially outwardly of the bowl and into the path of movement of the leading section of said wing structure, and means for rotating said mulling assembly in said one direction. 